Many adapters are known in the prior art, which have been designed for installation between the carburetor and the admission manifold of an internal combustion engine, in order to extract air from the atmosphere and inject the same towards the throats of the carburetor in order to improve the mixture of air and fuel and the economy in the utilization of said fuel. Some of said devices are illustrated and described in U.S. Pat. Nos. 1,029,898; 1,118,865; 1,558,605; 1,748,203; 1,942,187; 2,337,852; 3,973,534; 3,943,900; and 4,137,875. Other of said devices are shown and described in German Pat. No. 591,918; Austrian Pat. No. 146,751; British Pat. No. 362,941; British Pat. No. 379,951; French Pat. No. 632,416; Italian Pat. No. 258,061, Australian Pat. No. 143,514; and Mexican Pat. No. 124,232.
The devices shown and described in practically all of the above mentioned patents, are irrelevant to the device of the present invention, inasmuch as they provide apparatus having circumferential passages around the opening, and the air from the atmosphere is injected towards the passage before entering the opening of the auxiliary device for air admission. However, in U.S. Pat. No. 1,558,605 and in Austrian Pat. No. 146,751, a wire mesh or grid is placed across the opening, said grid being used in order to break the incoming mixture of fuel and air, and more air is injected towards the opening from the atmosphere through an orifice passing through the walls of the device but without entering towards the interior of the cavity.
On the other hand, in Mexican Pat. No. 124,232, granted to the same applicant of the instant application, a device is described for installation between the carburetor and the admission manifold of an internal combustion engine and is provided with one or more secondary air inlet pipes partially extending into the opening through which the fuel-air mixture passes, each of said tubes having, adjacent thereto, perforate dispersing plates which extend partially into the opening. The present application describes and claims an improvement with respect of the device of Mexican Pat. No. 124,232.
Finally, in U.S. Pat. No. 4,137,875, also granted to the same applicant hereof, there is described and claimed a device which is provided with a perforate plate covering the total area of the opening, on the lower part of the same, and a plurality of air distribution pipes is arranged on said perforate plate, said pipes being connected through openings and a filter with the exterior atmosphere, said pipes being perforate and containing, in the preferred embodiment of the invention, a plurality of branches, in order to suitably distribute the air throughout the opening, the said perforate plate also causing additional turbulences which increase the homogeneity of the mixture of air and fuel and, therefore, which increase the efficiency of the carburetor. The instant application also represents an improvement over the device described and illustrated in U.S. Pat. 4,137,875.
The device illustrated and described in Mexican Pat. No. 124,232, while highly efficient to improve to a great extent the efficiency of admixing of the air-fuel mixture, thereby producing a more homogeneous mixture and accomplishing a more complete and efficient combustion, in practice has shown certain slight deficiencies as to the production of a perfectly homogeneous mixture of air-fuel and with a sufficient amount of air to be completely burned without undue detonations in the cylinders of the engine to which the same is associated, in view of the fact that the turbulences created by the devices of the apparatus are not sufficient for the mixture to be perfectly homogenized when it reaches the cylinders of the engine. It is for this reason that the device of U. S. Pat. No. 4,137,875 was developed, in order to accomplish the goal of creating, with said device for improving the admixture of air-fuel, very energetic turbulences in view of the interception of the stream by a grid completely covering the opening, with which it was apparent that a better homogeneity of the mixture of air-fuel is accomplished for entering into the admission manifold of the associated engine. However, the provision of this complete grid or perforate plate in a certain way causes slight pressure drops in view of the friction caused by the orifices of the grid and, consequently, it tends to decrease to a certain extent the power of the engine, which represent a serious drawback in view of the fact that, while the device increases the efficiency of the use of the fuel, this is accomplished at the expense of the total power developed by the engine.
Therefore, for long the applicant has sought to improve the devices previously described, in order to overcome the drawbacks and to nevertheless provide the advantages of both devices, that is, the production of a perfectly homogeneous air-fuel mixture having the amount of air sufficient for a complete or practically complete combustion thereof and, at the same time, the obtention of a low pressure drop by friction through the grids of the previously described apparatus.